A nifty little summary of the strain on 3G networks: Carriers want the additional revenue, but networks are performing inconsistently around the country, as capacity in some markets hits the limits, Matt Richtel reports in the New York Times. Just putting in more cell base stations doesn't help, as it increase interference. Chips have to be smarter, carriers have to tune their networks, and, apparently, users just have to put up with it.
Not mentioned in the article, which focuses largely on AT&T's network, is that AT&T pushes Wi-Fi to its iPhone customers, which in turn provides a more predictable experience in urban areas indoors, while offloading traffic from the 3G network and reducing interference among active devices.
AT&T has foolishly opted to require iPhone users to request access at an AT&T hotspot through a cumbersome process. Instead, AT&T should push data from iPhones onto its Wi-Fi whenever possible, because the experience will certainly be comparable, and generally superior, given the backhaul AT&T has in its Wayport-acquired locations.
I remember when ATT was first opening up Starbucks wifi to iPhone users. I think they encountered people spoofing the iPhone browser to get on with their lappys. Could the SMS requirement be a workaround to authenticate users? If so, what else could they do?
The fact that AT&T can't authenticate phones on its own network at hotspots seems pretty silly. Devicescape made a piece of software for iPhone called Easy Wi-Fi (and a special one just for AT&T) that handles the whole transaction without bothering the users.
EAP-SIM based solutions can indeed handle the whole login/password transaction in the background giving the user a seamless handover experience. MNO's without their own affiliated WiFi networks can sign up with WiFi aggregators to push bandwidth intensive services over WiFi AND assuming the aggregator has strong international coverage, use the same for international data roaming.